body{margin:0;font-family:system-ui,sans-serif}main{max-width:480px;margin:48px auto;padding:0 16px}form{gap:8px;display:flex}form input{flex:1;padding:8px}ul{padding:0;list-style:none}li{border-bottom:1px solid #ddd;justify-content:space-between;align-items:center;padding:8px 0;display:flex}li.done label{color:#888;text-decoration:line-through}.error{color:#c00}